Finished lubricants, such as, for example, automatic transmission fluids (ATFs), can be manufactured by blending low viscosity base oils with very-high-molecular-weight polymers. The polymers are used to provide a higher viscosity at high operating temperatures, compared to the viscosity of the base fluid and additives alone. This increase in high-temperature viscosity must be obtained without comprising the viscosity at lower temperatures. That is, the finished lubricant must have excellent low temperature pumpability. Pumpability requirements limit the selection of polymers to those which have desired solubility characteristics over a wide temperature range. Polymethacrylate polymers are particularly preferred in ATF applications.